The correct option is D 0.371 g, 0.546 g
Phenolphthalein will only neutralise 50% of Na2CO3.
12 Milliequivalents of Na2CO3=Milliequivalents of H2SO4=0.1×17.5×2=3.5
∴ Milliequivalents of Na2CO3=7.0
WNa2CO3MNa2CO3×2×1000=7.0
∴ WNa2CO3=7.0×1062×1000=0.371 g
The methyl orange indicator will neutralise the rest 50% of Na2CO3 and original NaHCO3.
∴ 12 Milliequivalents of Na2CO3+Milliequivalents of NaHCO3=Milliequivalents of H2SO4=0.2×25×2=10
∴ Milliequivalents of NaHCO3=10−3.5=6.5
WNaHCO3MNaHCO3×1×1000=6.5
∴ WNaHCO3=6.5×841×1000=0.546 g